The present invention relates to the device being helpful to the safety running of the train. In particular, the present invention relates to a derailment prevention guard which guides a wheel against running off a main truck and a guard rail which prevents a derailed train from running away outside the track.
The outline of the derailment prevention guard and the guard rail will be described below. Further, the relation of the railway maintenance work, the derailment prevention guard and the guard rail will be described.
(1) The Derailment Prevention Guard
For example, when the train is running on the curved track, as shown in FIG. 26, it is generally conducted that a guard member, which guides a wheel 101 against running off a main rail 102, is arranged so as to be in parallel with the main rail 102 within the gauge. An example of derailment prevention structure comprising the guard member is shown in FIG. 27. In FIG. 27, a guard member 103 is arranged so as to be in parallel (being at right angles to a space) with the main rail 102, and the guard member 103 is fixed by tightening one set of a bolt 108 and a nut 109 and another set of a bolt 110 and a nut 111 through a block 104 and washers 105, 106 and 107. The guard member 103 is the derailment prevention guard. Although not shown, several sets of bolt-nut tightening structure are provided at right angles to a space.
(2) The Guard Rail
For example, when the train is running on the curved track, several guard rails are laid on the appropriate points to prevent a derailed train from running away outside the track and minimize damage from derailment even if the wheel 101 shown in FIG. 26 runs off the main rail 102. An example of the guard rail is shown in FIGS. 28 (a) (b). As shown in FIG. 28(a), guard rails 113, 113 are installed inside the gauge of main rails 112, 112. In the place having frequent fall of rocks and snowfall or the other place needing the guard rail, guard rails 114, 114 are installed outside the main rails 112, 112, as shown in FIG. 28(b).
(3) The Railway Maintenance Work
a. Track Bed Ballast Tamping by a Tie Tamper or a Multiple Tie Tamper
For preventing the track sinking, as shown in FIG. 29(a), the ballast 116 around underneath rails 115, 115 to which the most weight of train is given is tamped so as to become densely by a track bed ballast tamping machine called a tie tamper or a multiple tie tamper, when the occasion demands. The ballast 117 except ballast underneath the rails 115, 115 is made so as to relatively become sparsely. The reason is as follows. The load in the vertical direction given through the rails is the maximum around underneath the rails, and if the filling density of ballast 116 around underneath the rails 115, 115 is nearly the same as the filling density of ballast 117 except ballast underneath the rails 115, 115, the ballast 116 around underneath the rails 115, 115 becomes sparsely by the large weight from the rails 115, 115 and a sleeper 118 at the spot sinks. As a result, the track sinking is caused.
In view of the foregoing, as shown in FIG. 29 (a), for preventing the track sinking, the ballast 116 around underneath the rails 115, 115 to which the most weight of train is given is tamped so as to become densely by the tie tamper or the multiple tie tamper, and the ballast 117 except ballast underneath the rails 115, 115 is made so as to relatively become sparsely. The ballast 116 of a large filling density around underneath the rails 115, 115 carries the large weight from the rails 115, 115. Accordingly, the sleeper 118 does not sink.
But, as time goes by, as shown in FIG. 29 (b), the large weight from the rails 115, 115 causes the filling density of ballast 116 around underneath the rails 115, 115 to become sparsely little by little. So, before the filling density of ballast become sparsely so as to cause the track sinking, as shown in FIG. 29 (a), the ballast 116 around underneath the rails 115, 115 is tamped so as to become densely by the tie tamper or the multiple tie tamper.
b. Rail Grinding by a Rail Grinding Car
A rail grinding work by a rail grinding car is conducted to maintain the rails. This rail grinding work is conducted by a rail maintenance car and a rail grinding car. That is, the rail maintenance car carries a measuring device for evaluating objectively the comfortable degree to ride in by the data of magnitude of oscillation and direction of joggling of the train during running. The rail maintenance car runs on the rail at a predetermined interval (for example, a frequency of once or twice per year). If the data for evaluating the comfortable degree to ride in measured by the device exceeds a standard value, the rail grinding car grinds the unevenness part of rail so as to come up to the standard level while running on the corresponding rail. By the rail grinding work, since a value of magnitude of oscillation and direction of joggling of the train during running is limited within an appropriate range, a comfortable feeling to ride in can be obtained. The rail grinding work is conducted not only to the rail on the ballast track but also to the rail on the concrete slab track as shown in FIG. 30, if necessary. In FIG. 30, reference numeral 121 denotes a roadbed concrete, reference numeral 122 denotes a cement asphalt, reference numeral 123 denotes a concrete slab, and reference numeral 124 denotes a rail.
(4) The Relation Between the Range of Maintenance Work and the Derailment Prevention Guard or the Guard Rail
FIG. 31 shows the range of maintenance work by a tie tamper to the arrangement of a main rail 131 and a derailment prevention guard member 132. The oblique line parts denote the range of maintenance work by the tie tamper. That is, since the construction on the oblique line parts interferes with the ballast tamping work by the tie tamper or the rail grinding work, the above construction must be moved to the location except the oblique line parts before the ballast tamping work or the rail grinding work. That is, the derailment prevention guard member 132 shown in FIG. 31 hinders the ballast tamping work by the tie tamper and the work by the rail grinding car or the rail maintenance car. However, since the conventional derailment prevention guard member has a tightening structure using many pairs of bolts and nuts, the tightening work and the loosening work take plenty of time and are complicated. Furthermore, in order to avoid the interference with the ballast tamping work by the tie tamper and the work by the rail grinding car or the rail maintenance car, the heavy derailment prevention guard member must be moved to the permanent wayside by human power. So, there is a possibility of the problem on safety during the movement.
Likewise, the guard rails 113, 114 shown in FIGS. 28 (a) (b) hinder the ballast tamping work by the tie tamper and the rail grinding work. Accordingly, in order to avoid the interference with those works, the heavy guard rails must be moved to the permanent wayside by human power. So, there is a possibility of the problem on safety during the movement.